Project description:Classical genetics in model organisms has defined many signaling pathways that control cell movement and multicellular morphogenesis. However,these approaches have not succeeded in placing some established chemotaxis regulators, such as the MAP kinase kinase MEK1, in activator/effector pathways. Here, we combined morphological measurements with epistasis analysis of transcriptional phenotypes and found that the protein phosphatase 4 (PP4) signaling pathway controls Dictyostelium chemotaxis and development. PP4 is a phosphatase that regulates recovery from DNA damage. We show that Dictyostelium SMEK functions as the PP4R3 regulatory subunit and may regulate the subcellular localization of PP4 catalytic subunit PP4C. SMEK binds PP4C and the complex functions downstream of MEK1 to regulate chemotaxis and morphogenesis. Microarray analysis of gene expression in mutant strains indicated that PP4 controls leading edge formation and cellular responses to stress. Thus, the MEKPP4C/SMEK pathway has a direct role in regulating chemotaxis, in addition to regulating the DNA repair checkpoint. Keywords: Developmental time course series from 1 Dictyostelium wildtype and 5 chemotaxis mutants to determine epistatic relationship
Project description:au09-01_mpk mpk Mitogen Activated Protein Kinase (MAPK) signaling pathways are key regulators of cell proliferation, differentiation and stress effectors. The core of the MAP kinase signal transduction cascade is composed of a three-kinase module consisting of a MAP kinase kinase kinase (MAPKKK), a MAP kinase kinase (MAPKK), and a MAP kinase (MAPK). The signaling pathway is activated upon stimulation by a phosphorylation cascade.
Project description:au09-01_mpk mpk Mitogen Activated Protein Kinase (MAPK) signaling pathways are key regulators of cell proliferation, differentiation and stress effectors. The core of the MAP kinase signal transduction cascade is composed of a three-kinase module consisting of a MAP kinase kinase kinase (MAPKKK), a MAP kinase kinase (MAPKK), and a MAP kinase (MAPK). The signaling pathway is activated upon stimulation by a phosphorylation cascade. 2 dye-swap - wild type vs mutants
Project description:au09-01_mpk_flagellin - wt-col0_flagellin Mitogen Activated Protein Kinase (MAPK) signaling pathways are key regulators of cell proliferation, differentiation and stress effectors. The core of the MAP kinase signal transduction cascade is composed of a three-kinase module consisting of a MAP kinase kinase kinase (MAPKKK), a MAP kinase kinase (MAPKK), and a MAP kinase (MAPK). The signaling pathway is activated upon stimulation by a phosphorylation cascade. Flagellin is a protein present in the flagellum of almost all bacteria and triggers Innate Immunity in plants, mediated by a MAPK phosphorylation signal cascade. To better understand the changes occuring in wt-Col0 flagellin treatment at the gene expression level, we would like to perform a microarray transcriptomic analysis. 1 dye-swap - treated vs untreated comparison
Project description:We identified 3418 genes transcribed at a level of at least two copies each. We identified many transcripts involved in protein translation, cell maintenance and metabolism, as expected for vegetative cells. The most highly expressed cell signaling genes include ubiquitin, smlA, and nucleotide exchange factors RasGEF F and Ras GEF G. Additionally, we identified many genes previously reported to be expressed only during later stages of development including dutA, actin8, thioredoxin3, culmination specific protein 45D, discoidin II and yelA.
Project description:au09-01_mpk_flagellin - wt-col0_flagellin Mitogen Activated Protein Kinase (MAPK) signaling pathways are key regulators of cell proliferation, differentiation and stress effectors. The core of the MAP kinase signal transduction cascade is composed of a three-kinase module consisting of a MAP kinase kinase kinase (MAPKKK), a MAP kinase kinase (MAPKK), and a MAP kinase (MAPK). The signaling pathway is activated upon stimulation by a phosphorylation cascade. Flagellin is a protein present in the flagellum of almost all bacteria and triggers Innate Immunity in plants, mediated by a MAPK phosphorylation signal cascade. To better understand the changes occuring in wt-Col0 flagellin treatment at the gene expression level, we would like to perform a microarray transcriptomic analysis.
Project description:au08-06_mpk6_heat_stressed - au08-06_mpk6_heat_stressed - Mitogen Activated Protein Kinase (MAPK) signaling pathways are key regulators of cell proliferation, differentiation and stress effectors. The core of the MAP kinase signal transduction cascade is composed of a three-kinase module consisting of a MAP kinase kinase kinase (MAPKKK), a MAP kinase kinase (MAPKK), and a MAP kinase (MAPK). The signaling pathway is activated upon stimulation by a phosphorylation cascade. In previous studies, it was shown that the mpk6 KO mutant plants are significantly more tolerant to heat stress in comparison to wt and that after 3h treatment at 37°C, an activation of heat-shock proteins occures in the mpk6 mutant. To better understand the changes occuring in the mpk6 mutant upon heat stress at the gene expression level, we would like to perform a microarray transcriptomic analysis. - Mitogen Activated Protein Kinase (MAPK) signaling pathways are key regulators of cell proliferation, differentiation and stress effectors. The core of the MAP kinase signal transduction cascade is composed of a three-kinase module consisting of a MAP kinase kinase kinase (MAPKKK), a MAP kinase kinase (MAPKK), and a MAP kinase (MAPK). The signaling pathway is activated upon stimulation by a phosphorylation cascade. In previous studies, it was shown that the mpk6 KO mutant plants are significantly more tolerant to heat stress in comparison to wt and that after 3h treatment at 37°C, an activation of heat-shock proteins occures in the mpk6 mutant. To better understand the changes occuring in the mpk6 mutant upon heat stress at the gene expression level, we would like to perform a microarray transcriptomic analysis. Keywords: treated vs untreated comparison 4 dye-swap - CATMA arrays
Project description:Small RNAs play crucial roles in regulation of gene expression in many eukaryotes. Here, we report the cloning and characterization of 18-26 nt RNAs in the social amoeba Dictyostelium discoideum. This survey uncovered developmentally regulated microRNA candidates whose biogenesis, at least in one case, is dependent on a Dicer homolog, DrnB. Furthermore, we identified a large number of 21 nt RNAs originating from the DIRS-1 retrotransposon, clusters of which have been suggested to constitute centromeres. Small RNAs from another retrotransposon, Skipper, were significantly up-regulated in strains depleted of the second Dicer-like protein, DrnA, and a putative RNA-dependent RNA polymerase, RrpC. In contrast, the expression of DIRS-1 small RNAs was not altered in any of the analyzed strains. This suggests the presence of multiple RNAi pathways in D. discoideum. In addition, we isolated several small RNAs with antisense complementarity to mRNAs. Three of these mRNAs are developmentally regulated. Interestingly, all three corresponding genes express longer antisense RNAs from which the small RNAs may originate. In at least one case, the longer antisense RNA is complementary to the spliced but not the unspliced pre-mRNA, indicating synthesis by an RNA-dependent RNA polymerase. Keywords: cDNA library; small RNA sequencing
Project description:au08-06_mpk6_heat_stressed - au08-06_mpk6_heat_stressed - Mitogen Activated Protein Kinase (MAPK) signaling pathways are key regulators of cell proliferation, differentiation and stress effectors. The core of the MAP kinase signal transduction cascade is composed of a three-kinase module consisting of a MAP kinase kinase kinase (MAPKKK), a MAP kinase kinase (MAPKK), and a MAP kinase (MAPK). The signaling pathway is activated upon stimulation by a phosphorylation cascade. In previous studies, it was shown that the mpk6 KO mutant plants are significantly more tolerant to heat stress in comparison to wt and that after 3h treatment at 37°C, an activation of heat-shock proteins occures in the mpk6 mutant. To better understand the changes occuring in the mpk6 mutant upon heat stress at the gene expression level, we would like to perform a microarray transcriptomic analysis. - Mitogen Activated Protein Kinase (MAPK) signaling pathways are key regulators of cell proliferation, differentiation and stress effectors. The core of the MAP kinase signal transduction cascade is composed of a three-kinase module consisting of a MAP kinase kinase kinase (MAPKKK), a MAP kinase kinase (MAPKK), and a MAP kinase (MAPK). The signaling pathway is activated upon stimulation by a phosphorylation cascade. In previous studies, it was shown that the mpk6 KO mutant plants are significantly more tolerant to heat stress in comparison to wt and that after 3h treatment at 37°C, an activation of heat-shock proteins occures in the mpk6 mutant. To better understand the changes occuring in the mpk6 mutant upon heat stress at the gene expression level, we would like to perform a microarray transcriptomic analysis. Keywords: treated vs untreated comparison